This chapter describes the preparation of some common reagents used in biochemistry laboratory. Preparation of some dilute acids, preparation of some dilute bases and preparation of some general reagents are covered in this chapter. Some general reagents are agar, aluminium chloride, ammonia, ammonium molybdate solution, ammonium oxalate, amylase solution, Barfoed’s reagent, barium chloride, benedict’s solution, biuret reagent, calcium hydroxide solution (lime water), cholesterol standard stock, cholesterol working standard, Fehling\'s solution, formalin solution (dilute), glucose solution (1%), Hopkins-Cole reagent etc. briefly explained in this chapter.